The present invention relates to a fan assembly.
A vacuum cleaner includes a fan. The fan has an impeller rotated by a motor to drive a flow of working air through the vacuum cleaner. Dirt from household surfaces is entrained in the flow of working air. The dirt is thus transported through the vacuum cleaner into a filter bag.
The present invention is an apparatus comprising an open frame motor. The motor is coupled to an output shaft rotatable about an axis, and has an axially front end and an axially rear end. An impeller is mounted on the shaft and rotated about the axis by the shaft. The impeller is configured to drive air radially outward from the impeller upon rotation of the impeller. A housing has an air flow inlet, an air flow outlet, and a closed inner wall surface. The closed inner wall surface extends from the inlet to the outlet and surrounds the motor and the impeller. The inner wall surface is located radially outward of the impeller axially from a first location forward of the impeller to a second location rearward of the front end of the motor. The closed inner wall surface defines a peripheral boundary of an air flow path extending alongside the impeller and the motor from the first location to a third location rearward of the motor. The air driven radially outward from the impeller is guided by the inner wall surface to flow alongside the motor to cool the motor.
In one preferred embodiment, the second location is located rearward of the motor, the impeller is located axially forward of the motor, the inlet is located axially forward of the impeller, and the outlet is located axially rearward of the motor. The impeller has a backplate with primary vanes extending from the backplate axially away from the motor and supplementary vanes extending from the backplate axially toward the motor.
A radially extending plate is attached to the housing. The plate is located axially between the motor and the impeller with an axially extending channel located between the plate and the inner wall surface. The channel defines part of the working air flow path. The plate is configured to direct the air radially outward toward the channel. It is further configured to support the motor. The plate has a pocket for seating a bearing that supports the shaft. At least one axially extending hole in the plate enables a circulating airflow in which the air flows frontward through the hole, radially outward in front of the plate, rearward through the channel, and radially inward behind the plate.